private void ShowHelp(Context context)
 {
     if (string.IsNullOrEmpty(context.WorkFlow.Properties["HelpFile"].ToString(context)))
     {
         return;
     }
     try
     {
         var stream = Workflow.GetFileStream(context.WorkFlow.Properties["HelpFile"].ToString(context));
         if (stream != null)
         {
             var view = new HelpView(stream);
             view.ShowDialog();
             stream.Close();
         }
     }
     catch (Exception e)
     {
         Log.Error("Show help error", e);
     }
 }